docDFW Heronries - City of Carrollton, TX
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DFW Heronries - City of Carrollton, TX
DFW Heronries Brett Johnson Urban Wildlife Biologist Texas Parks and Wildlife Dept. Today’s Topics Species of Interest Protection Issues Early Detection Deterrent Methods Habitat Modification Today’s Topics Species of Interest Protection Issues Early Detection Deterrent Methods Habitat Modification Cattle Egret Historically native to parts of Asia, Africa and Europe Extremely fast range expansion Seem to follow spread of cattle ―Empty Niche‖ - no real competition 1st Appear - 1941 1st US breeding – 1953 Most abundant species in heronries Cattle Egret Protected under the MBTA ―The Cattle Egret got here by means of a natural range expansion. They were not intentionally introduced or accidently released. They followed the increase of cattle production worldwide and have long range migration. They also pose no immediate threat to ―native‖ species. So they ARE legally covered under the MBTA.‖ USFWS Wildlife Biologist Cattle Egret Bill — yellow to orange Short, thick neck Hunched posture Yellowish legs Fly in ―V‖ pattern formation Breed - Late April-October Little Blue Heron Typically 2nd most abundant* Dark slate-blue body Maroon-brown head, neck Legs blue-green Breeding season extends from late March to late July Snowy Egret 3rd Most Common Bill is thin, long and black Black legs Bright yellow feet Long, slender neck Breeding season extends usually from late March to early August Great Egret Big, white bird Bill is long and yellow Legs and feet are black # in heronry varies widely Breeding season extends from early March to early August Today’s Topics Species of Interest Protection Issues Early Detection Deterrent Methods Habitat Modification Migratory Bird Treaty Act of 1918 • This 1918 Act implemented the 1916 convention between the United States and Great Britain (for Canada) • Similar conventions between the United States and Mexico (1936), Japan (1972) and the Union of Soviet Socialists Republics (1976) • Each new treaty has been incorporated into the MBTA as an amendment and the provisions of the new treaty are implemented domestically • Established Federal responsibilities for the protection of nearly all species of birds, their eggs and nests • 836 species are legally protected, 58 legally hunted MBTA Protection • Made it illegal for people to "take" migratory birds, their eggs, feathers or nests • Take is defined in the MBTA to include by any means or in any manner (even unintentional), any attempt at hunting, pursuing, wounding, killing, possessing or transporting any migratory bird, nest, egg or part thereof What can and cannot be done legally? “Simply put, it is prohibited to kill the birds or harass them in any way that would cause the abandonment and death of eggs or hatchlings. Anything short of this is not a violation of the MBTA.” USFWS Wildlife Biologist What is the difference between roosting and nesting? ―Birds don't typically sit on a nest when roosting outside the nesting season. Almost anything can be done to drive them away when they are only roosting.‖ USFWS Wildlife Biologist When is it too late to harass the birds? ―The window of opportunity is fairly short, from the time the birds first arrive until an egg is laid in a nest.‖ USFWS Wildlife Biologist What about destroying nests BEFORE nesting? “A newly built nest can be destroyed up until the moment an egg is laid. After that, it may be removed only after the nest is no longer used by the parent birds rearing offspring.” End of nesting season nest removal “In cases where a colony is no longer active (i.e. no evidence of the colonial species using the colony site for nesting purposes in the current year), then those old nests may be destroyed at any time without the need for a permit.” Interim Empty Nest Policy of the U. S. Fish and Wildlife Service, Region 2 ―Take of nests in partially or fully active colonies must be done by trained, permitted Wildlife Services personnel‖ Interim Empty Nest Policy of the U. S. Fish and Wildlife Service, Region 2 ―Active or Partially Active Colonies. Once egg laying has commenced by any of those birds, all nest destruction must cease. Destruction of empty nests in an active or partially active colony will likely threaten surrounding nests that contain eggs or nestlings; therefore it will not be allowed except on a case-by-case basis as determined by the Migratory Bird Permits Office.‖ Interim Empty Nest Policy of the U. S. Fish and Wildlife Service, Region 2 ―Nest destruction may resume at the end of the nesting season without a permit only after all nesting activities by all birds in the colony have ceased, which should be by October 1 (i.e. after all nestlings have fledged and left the site and no eggs are being incubated by late nesters). At such time nests containing infertile/abandoned/dead eggs or long-dead nestlings may also be destroyed without permit.‖ Interim Empty Nest Policy of the U. S. Fish and Wildlife Service, Region 2 If the window on harassment is missed and the first egg is in the nest: “Permits to take active nests (containing eggs or nestlings) of colonial species for Depredation Control purposes will not be issued by the Migratory Bird Permits Office. Destruction of such active nests must be done by trained personnel of the U.S.D.A. - Wildlife Services.” Today’s Topics Species of Interest Protection Issues Early Detection Deterrent Methods Habitat Modification ―The best way to prevent the establishment of a heronry is through public awareness and early detection. If detected early when the birds first move in, they are nervous and can be easily moved with various scaring methods‖ NUISANCE HERONRIES IN TEXAS: CHARACTERISTICS AND MANAGEMENT — Second Edition — ―Municipal administrators should consider providing training information on heronry characteristics and initiation to city police, maintenance personnel and interested volunteers. A comprehensive vigil during the early spring could avert later undesirable circumstances for both people and birds.‖ NUISANCE HERONRIES IN TEXAS: CHARACTERISTICS AND MANAGEMENT — Second Edition — Today’s Topics Species of Interest Protection Issues Early Detection Deterrent Methods Habitat Modification ―Scaring devices such as pyrotechnics (screamers, badgers), cracker shells (shot from a 12-gauge shotgun), rope-firecrackers and propane cannons all work effectively‖ To be most effective, combine several of these methods so that the birds do not become accustomed to them. Scare-eye type balloons have been effective with SENTRY birds Today’s Topics Species of Interest Protection Issues Early Detection Deterrent Methods Habitat Modification ―Dramatic changes are not necessary. Such modifications of a potential nesting area usually produce longer lasting prevention than other deterrent methods.‖ Spacing between tree canopies Open canopies Egrets LIKE >75% canopy closure Today’s Topics Species of Interest Protection Issues Early Detection Deterrent Methods Habitat Modification Success depends on your participation: • If your trees have nests, remove them now • Consider thinning tree canopy • Use visual deterrents • If you noticed sentry birds, report this activity immediately • Consider helping your neighbor Questions will be addressed by panel at the end of the workshop Brett Johnson Urban Wildlife Biologist Texas Parks and Wildlife Deparment 972-293-3841 dallasbiologist@airmail.net
